http://flightaware.com/live/flight/NWA123T
It’s said this bygone airliner flies the skies under dark skies unable to go quietly into obvilion…
Ok ok, seriously. I just thought this was odd. Someone filing a bogus flight plan perhaps?
Kind of curious who is the operator of that 737-600, as Sweetwater does not have service of that kind, and last I checked no US carriers were using the -600, except for “Janet”.
The NWA designation may be available now to a new operator that just isn’t in the system yet. With a T at the end of the flight number meaning this one is a Test flight for someone. Keep an eye on it, soon you may see a P at the end of the flight number meaning a Proving flight, then it’s close to going into service.
I show current 737-600 ops as Air Algerie, A private Charter, Malev Hungarian and West Jet. No NWA.
My guess is that it’s a flight plan for FAA testing purposes that accidentally escaped the testing environment.
SAS also operated 737-600’s.
I think you’re right. Just for boredom’s sake I went through the liveatc archives for +/- one hour the ETD and didn’t hear anything. +1 for you.
And if you look at the FA track it’s all ‘estimated’. Never happened IMO.
I know that Delta still owns the Northwest Airlines name and logo etc., not sure, now that you say that, if that would mean they also own the rights to the call sign.
…OR perhaps NWA is going to branch back off of Delta and take over MSP again!! 
Still miss those red tails…
See my posting 2 below yours.
In all of my years of flight tracking, I have yet to see an airline use T or P for a test flight or a positioning flight. Most airlines use a specific range of flight numbers for test and positioning (i.e. ferry or deadhead) flights. These flight numbers are 4 digits long and quite often begin with 9.
I have the feeling that the reuse of a designator isn’t done for several years after the designation is no longer in use.